Microplastic pollution causes harm to marine animals through ingestion, entanglement, and toxicity. Reducing plastic pollution is essential for marine animal welfare.
Marine plastic pollution causes welfare harms at multiple scales: individual animals suffer from ingestion of macroplastics that cause blockage and false satiation, entanglement in plastic debris that causes injury and drowning, and exposure to concentrated toxins from microplastic surfaces. Sea turtles, seabirds, and marine mammals are most visibly affected, but microplastic ingestion is now documented across the marine food web. The welfare harm from plastic is diffuse and often invisible, making it harder to mobilise concern than obvious individual harms. Consumer action to reduce single-use plastic use, corporate plastic reduction commitments, and policy interventions including plastic taxes and extended producer responsibility are all effective responses.